端粒酶各组分在肿瘤细胞分化过程中的表达和调控研究

The methods to detect the mRNA level of hTERT, hTR, hTP1 and hTERT mRNA splicing variants were established .On the base , the molecular mechanism of telomerase regulation in tumor cell differentiation and cell apoptosis induced by drugs and the effect of DNA-damageing drugs on telomerase activity were studied. In all-trans-retinoic acid (ATRA)-induced , human leukemia HL-60 cells differentiation, telomerase activity was down-regulated associated with a decrease in hTERT mRNA and an increase in hTP1 mRNA. However, the alternative splicing of hTERT mRNA may not contribute to the suppression of telomerase activity induced by ATRA. On the other hand, we investigated the relationship between telomerase activity and anti-cancer effect of DNA damaging anti-tumor drugs on human lung adenocarcinoma A549 cells . The results suggested that salvicine, a novel topoisomerase II inhibitor developed in our institute, may partly perform its function through modulation of telomerase activity by dephosphorylation of telomerase components, and the decrease of telomerase activity is an early and specific response to salvicine-treatment compared with other DNA damaging drugs. In the subsequent project, the model of apoptosis induction by salvicine was used to reveal the change of telomerase activity in cell apoptosis. Telomerase activity was also down-rgulated in salvicine-induced HL-60 cell apoptosis, and protein phosphatase PP2A was activated at the same time. The results collectively suggested that the salvicine-induced decline in telomerase activity may be principally by the dephophorylation of twlomerase components mediated by PP2A.

建立端粒酶各组分hTRT, hTR, TP1的基因表达半定量测定技术；利用恶性肿瘤细胞株分化模型，主要是白血病和肝癌细胞株，研究其分化逆转过程中端粒酶活力及其相关基因的表达调节；构建c-fos表达载体转染肿瘤细胞系，研究其和端粒酶催化亚基hTRT表达的相关性。此钛芯慷杂诮沂径肆Ｃ傅募せ罨疲髌湓谥琢龇⑸⒄构讨械淖饔糜兄匾庖澹币参滦涂拱┮┪锒肆Ｃ敢种萍恋目⑻峁└嗟睦砺垡谰荨